This invention refers to a heating device for the vaporization of active substances, that is applicable to certain types of vessels containing active substances that, having a wick with one end introduced in the vessel and therefore immersed in the active substance, the opposite end of this wick emerging externally so that by capillary action the active substance reaches that external and free end, all so that the heating of the wick produce the vaporization of the corresponding active substance. The heating taking place by means of electrical resistances positioned in the device.
The purpose of the invention is to provide a heating device that includes one or more electrical resistances whose activation produces the heating of a wick that passes through an axial opening in the device, said wick is partly immersed in an active liquid substance contained in a vessel on which the actual device is mounted, the basic purpose of the invention being that the support body for the electrical resistance or resistances be formed from a single piece of moulded plastic.
There are numerous heating devices designed to produce the vaporization of active substances, such as disinfectants, insecticides, air-fresheners, germicides, fungicides, etc., two main types being distinguishable, one of them based on the heating of a PTC element that is usually situated between two high thermal conductivity coefficient electrodes, so that, with the correct electrical supply to the electrodes, the PTC referred to is heated and the consequent vaporization of an active substance that, by capillary action, reaches the free and upper end of a wick that emerges through an axial opening provided in the device assembly, this being mounted in the entrance of the vessel, containing the active substance.
As an example of this first type of device, the Patent of Invention 9600482 might be quoted, where the device is made up with a minimum number of pieces that logically facilitate its assembly and reduces manufacturing costs, among other advantages.
A second type of device is based on the heating of the wick by means of electrical resistances, and in this sense Spanish Utility Model Nxc2x0 9501364 and the European Patent EP 0689766 A1 can be quoted, so that in the first case the heating device includes a multitude of pieces that must be suitably assembled for the operation to be effective, which undoubtedly requires qualified personnel, care in assembly, etc., while in the second case, in the device of the European Patent, the electrical resistances are mounted on a printed circuit with an adequate power supply which requires an appropriate space or area within the device assembly for the positioning and correct placing of the printed circuit board.
Evidently, the use of electrical resistances is more economic than the use of PTC elements, although, as has just been stated, the two types of devices referred to, and that include electrical resistances as heating elements, have drawbacks not resolved at present.
The heating device that is proposed has been planned precisely to resolve the forementioned difficulties, for which a body has been envisaged in which the electrical resistances or resistance are mounted, in the case of there being only one, and with a supplementary piece acting as a clip set up on the actual body the effective and proper connection of the ends of the electrical resistances with the corresponding contactors is achieved, all in a such way that the said body for all the unit is formed from a single piece of moulded plastic, the preferred material being polyoliphene, such as polyamide, of low cost and, since it allows the possibility of working at a higher temperature, is more appropriate.
More specifically, the plastic moulded body as a single part of the device, supplemented by the forementioned clip, has a cylindrical configuration with a concentric opening fitted with an axial neck, so that between this neck and the side surface of the cylindrical body a diametrically opposed pair of ribs are established, for locating each resistance, with the particularity that in the case that three heating resistances were mounted in the device, then the number of ribs would be three, arranged about a 180xc2x0 contour, with which the angular separation would be 90xc2x0, as two of them remain diametrically opposite each other.
In this way the resistance or resistances are secured, these can be MO(metal oxide), ceramic, coiled wire, carbon or silicon type.
The body, besides the previously mentioned ribs, also has internal projections, whose number will be similar to the number of resistances plus one in the case of mounting in series, and equal to the number of resistances in the case of mounting in parallel, which projections are fitted with a pair of flutes forming a cross for the positioning of the ends of the wires of the electrical resistances, and the corresponding connection of the adjacent ends of two resistances, with the particularity that in those cross channels of the forementioned projections the ends of the resistances connected to each other can remain perfectly secured, and these staying supported by themselves without the need of the forementioned ribs.
As regards the part or piece that acts as a clip to establish electrical contact between the corresponding contactors and the ends of the heating resistance wires, it consists of a rectangular metallic sheet part, with an arm obtained by making a cutaway without detaching material, setting up a horizontal support surface on the upper part of the projections in which the ends of the heating resistance wires are positioned, preventing these wires from leaving the channels formed in those projections, and at the same time allowing the connection with the contactors, that are duly guided through a slot formed lengthwise in the upper and vertical section of the corresponding clip, in which there are some flaps, also obtained by making a cutaway without detaching the material, for establishment the corresponding connection.
Optionally the assembly or device in question can incorporate a cover with complete closing of the unit, in order to provide it with greater safety and not to leave the resistances nor their wires exposed, neither of course the contactor attachment clips, although the absence of the cover doesn""t imply that the device doesn""t offer maximum safety, since the assembly is placed within a general casing.
The cover, when it is included in the unit, will be fitted to the base of the heater and to its chimney, being supported only by the upper edge of the walls and respecting the irregular shape of that wall, without adding any height to the device when seen without the cover. Furthermore, such a cover will give a greater reliability in the positioning of the clips, being supported by them by means of three or four supports depending on whether two or three resistances are used in the heater.
By means of the device referred to a cost reduction is achieved due to the fact that resistances are more economic components than the PTC elements, the cost being similarly reduced due to the simplification of the number of parts and to the elimination of the corresponding closing cover, without forgetting that energy use is optimum compared with other devices with the same purpose.